1. Field of the Invention
The present invention relates to a securing member for exterior members and an exterior structure of a building.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2002-220910 (Patent Document 1) and Japanese Unexamined Patent Application Publication No. 2002-81186 (Patent Document 2) disclose securing members for exterior members. The securing members according to Patent Documents 1 and 2 are used to secure exterior members of a four-side shiplap structure. Each securing member includes a fixing portion that is fixed to a framework, a supporting portion that projects from the fixing portion, an upper engagement portion provided on the supporting portion so as to extend upward, and a lower engagement portion provided on the supporting portion so as to extend downward. The supporting portion supports two exterior members that are located at an upper side. The upper engagement portion engages with the two exterior members at the upper side. The lower engagement portion engages with two exterior members that are located at a lower side.
Each securing member further includes a fixing hole that is formed in the fixing portion and through which a fastener is inserted, and an erected portion that is disposed between opposing ends of the two exterior members at the lower side.
The securing member disclosed in Patent Document 1 includes a plurality of fixing holes that are formed in an upper section of the fixing portion and through which screws, which serve as fasteners, are inserted. The erected portion projects from a lower section of the fixing portion.
More specifically, the securing member disclosed in Patent Document 1 includes a pair of spacer portions at both sides of the fixing portion. The pair of spacer portions are bent so as to project toward the front of the securing member. Contact surfaces are formed at the distal ends of the pair of spacer portions so as to extend vertically. The contact surfaces support back surfaces of four exterior members that are vertically and horizontally adjacent to each other. The upper engagement portion engages with the two exterior members at the upper side. The lower engagement portion engages with the two exterior members at the lower side. The erected portion is formed on a lower section of the fixing portion. The erected portion is disposed between the opposing ends of the two exterior members at the lower side so as to prevent sideways displacement of the exterior members.
The securing member disclosed in Patent Document 2 includes a sealing member and an attaching member that are combined together. The sealing member has a plurality of through holes formed in an upper section of the fixing portion, and the attaching member also has a plurality of through holes formed in a step portion and a fixing plate portion so as to correspond to the through holes in the sealing member. The erected portion projects from a lower section of the fixing portion of the sealing member.
A securing member disclosed in Japanese Unexamined Patent Application Publication No. 2001-220882 (Patent Document 3) includes a bulging portion. The bulging portion has an opening. A section of the bulging portion that is above the opening and two ribs that project at locations below the opening form contact surfaces. An upper engagement portion and a lower engagement portion are raised at the periphery of the opening in the bulging portion.
A securing member disclosed in Japanese Unexamined Patent Application Publication No. 2007-262777 (Patent Document 4) also includes a bulging portion. The bulging portion includes a pair of further bulging portions that further bulge at one and the other sides of the bulging portion in the width direction, and has an opening. Contact surfaces are formed at the distal ends of the pair of further bulging portions so as to extend vertically. An upper engagement portion and a lower engagement portion are raised at the periphery of the opening in the bulging portion.
In the securing member disclosed in Patent Document 1, one of the through holes that is closest to the center line of the fixing portion in the width direction is disposed on the center line, and the erected portion is displaced from the center line in the width direction. Therefore, when the load of the exterior members is supported by the supporting portion, the upper engagement portion, and the lower engagement portion, the length over which two of the exterior members that are located at one side in the width direction are supported is not equal to the length over which two of the exterior members that are located at the other side in the width direction are supported. Thus, the load is not easily balanced between one and the other sides in the width direction.
In the securing member disclosed in Patent Document 2, one of the through holes that is closest to the center line of the fixing portion in the width direction is disposed on the center line, and the erected portion is also disposed on the center line in the width direction. Therefore, when the load of the exterior members is supported by the supporting portion, the upper engagement portion, and the lower engagement portion, the length over which two of the exterior members that are located at one side in the width direction are supported is equal to the length over which two of the exterior members that are located at the other side in the width direction are supported. Thus, the load is balanced between one and the other sides in the width direction.
However, in the case where the securing member is fixed to a thin structural member, if the securing member is fixed to the structural member so that the abutting line between the front surfaces of the two exterior members at the lower side is near the center of the structural member, the erected portion on the center line of the fixing portion in the width direction is easily disposed near a side surface of the structural member. Accordingly, the through hole on the center line is also easily disposed near the side surface of the structural member. In such a case, there is a risk that the fastener, such as a nail or a screw, that is inserted through the through hole on the center line will protrude from the side surface of the structural member or the side surface of the structural member will break.
Thus, when the above-described securing members according to the related art are used, it is difficult to support the load of the exterior members with good balance in the width direction, and it is also difficult to ensure good construction performance when the securing members are fixed to a thin structural member.
In the securing members disclosed in Patent Documents 1, 3, and 4, the contact surfaces tend to be long in the vertical direction to ensure that the contact surfaces have a sufficiently large area to stably support the exterior members. Accordingly, when the exterior members receive a rotating force due to wind pressure or the like, corners of the contact surfaces easily abut against the back surfaces of the exterior members. As a result, there is a risk that the back surfaces of the exterior members will be damaged by the securing members disclosed in Patent Documents 1, 3, and 4.